The deal would see Heineken take 1,895 of the Punch pubs and Patron Capital would take the remaining 1,329 outlets in the pub estate.

Heineken already owns around 1,100 UK leased and managed pubs it acquired from Royal Bank of Scotland in 2008 which are managed by its Star Pubs & Bars division.

The CMA said it is “considering whether it is or may be the case that this transaction, if carried into effect, will result in the creation of a relevant merger situation” and if so, “whether the creation of that situation may be expected to result in a substantial lessening of competition”.

The deal would see Heineken take 1,895 of the Punch pubs and Patron Capital would take the remaining 1,329 outlets in the pub estate (Image: Heineken/PA Wire)

It has set a deadline of March 2 for comments on the Punch takeover and will make a decision on whether to take further action by April 24.

The Scottish Licensed Trade Association (SLTA) has already voiced its concerns about the takeover, which would increase Heineken's market share in Scotland from around 2.0 per cent at present to 6.0 per cent and accused Heineken of focusing investment on city centre bars over smaller local pubs.

SLTA chief executive Paul Waterson believes the tie-up would also have a “disastrous effect on consumer choice”.

Waterson said: “We are delighted that the CMA has chosen to listen to the concerns voiced by so many businesses, organisations and individuals within the pub and brewing industry and open an investigation into Heineken’s takeover bid for Punch Taverns.

“Heineken is a global brewer, with very different priorities to their customers who often rely on hard earned local relationships to make their businesses work.

“We know from both Heineken’s words and actions that they will give preference to their own products across their estate, and this is simply not fair for brewers, publicans or consumers.

“We look forward to receiving the findings of the investigation.”

Heineken said in a full-year results announcement on Wednesday it hoped the Punch deal would go through by the end of the first half of 2017.

The Dutch group reported a 4.8 per cent increase in organic revenues though group revenue took a €1.15bn currency hit (£976m) as a result of negative foreign exchange rates, including the lower value of sterling against other currencies.

Pre-tax profits dipped 15 per cent to €2.4bn (£2bn), though the prior year had included a gain from the sale of its Mexican packaging business, Empaque.

Heineken also warned of “volatile” economic conditions ahead in 2017 and expects to book a further currency hit of up to €75m euros (£64m).